Fusible aromatic nitrocompound explosive composition containing particular wax as a desensitizer



United States Patent Int. Cl. C06!) 9/64, 15/02, 3/00 US. Cl. 149-92 1Claims ABSTRACT OF THE DISCLOSURE Explosive compositions on a basis offusible aromatic nitrocompounds and nitramines and/ or nitric estershaving incorporated therein as desensitizer a wax of a mixture ofpolychloronaphthalenes obtained in the chlorination and refining ofnaphthalene.

This invention relates to the use of soluble desensitizers for thedesensitization of castable explosives prepared on a basis of aromaticnitrocompounds and nitramines and/ or nitric esters.

More particularly this invention relates to the use of waxes comprisinga mixture of polychloronaphthalenes obtained in the chlorination andrefining of naphthalene. for the desensitization of castable explosivesprepared on a basis of aromatic nitro compounds and nitramines and/ ornitric esters and/or powdered metals and/or known desensitizers.

The aforesaid waxes are soluble in aromatic nitro compounds and areknown under the commercial name Nibrenwaches. (Literature source:Ullmanns Encyclopadie der Technischen Chemie, publishing house Urban &Schwarze'nberg, Munich-Berlin, 1954, vol. 5, page 474.) Nibrenwachs hereis a mixture of polychloronaphthalenes. The production of these mixturesof isomeric polychloronaphthalenes is mentioned, for example, in the US.Patent 1,111,289 and in the German Patent 548,260 (compare Ullmann, page474).

It is known that castable explosives prepared on a basis of aromaticnitro compounds and nitramines and/ or nitric esters can be desensitizedby the addition of waxes thereto; for exacple, 1% wax is often added toComposition B (60 parts hexogen, 40 parts trinitrotoluene) and also tothe Pentolite mixture (50 parts pentaerythritol tetranitrate and 50parts trinitrotoluene). The latter wax is not soluble in molten TNT. Inorder to form a stable emulsion of the explosive and wax, emulsifyingaids are often added, as for example, lecithin as an emulsifier andnitrocellulose as a stabilizer.

In addition, waxes and the necessary accompanying emulsifying aids arefrequently added to metalcontaining explosive mixtures, such as, forexample, a mixture of The use of such waxes and the accompanyingemulsifying aids, however, is associated with disadvantages. Since wax,lecithin and nitrocellulose are natural substances or derivatives ofnatural substances, their characteristics can- 3,472,713 Patented Oct.14, 1969 not always be precisely controlled and accordingly theformation of a stable emulsion is not always assured. Furthermore, thewaxes used hitherto were characterized by a low density, so that theresultant density of the entire explosive mixture was lowered.

These disadvantages can be eliminated by employing as desensitizersoluble waxes, that is waxes soluble in the explosive mixture. Thesolubility of the desensitizer waxes make it possible to proceed withoutresorting to an emulsion, the latter being often quite difficult toprepare. Furthermore, the aforesaid soluble waxes having high densitiesand namely densities in the range of 1.5 to 1.7 g./ cm.

It is most surprising that, in comparison to the other waxes, and namelythe insoluble waxes, a better desensitization to rapid heating isachieved by the use of the soluble Waxes, while desensitization to shockand impact is substantially equal to that realized with the waxes usedhitherto.

The desensitizing effect of the wax additives, in accordance with theinvention as compared to the insoluble waxes, was measured in thefollowing manner: 0.4 g. of an explosive mixture without wax or with aninsoluble or soluble wax was placed in a glass reaction vessel either inthe form of a single piece or in a finely ground state. The glass vesselwas then immersed in a molten bath of Woods metal. The molten metal bathwas then adjusted to a constant predetermined temperature. The time ittook to produce flashing or explosion of the mixture was thendetermined. The longer the period of time, the more tolerant theexplosive mixture is of thermal stresses.

EXAMPLE 1 The time required to produce flashing or explosion of TNT withand without desensitizers, was measured at 340 C. The following datawere obtained:

Seconds parts TNT 74 30 parts TNT, 5 parts Nibrenwachs D 116 (softeningpoint: 113 C.; dropping point: 116 C.; specific density: 1.66 g./cm.content of chlorine:52

54%) 82 30 parts TNT, 5 parts Nibrenwachs D (softening point: 130 C.;dropping point: 132 C.; specific density: 1.73 g./cm. content ofchlorine: 57- 59%) 82 30 parts TNT, 5 parts Montan wax 35 The aboveexample clearly establishes that Nibrenwachs, when used according to theinvention, acts as a better desensitizer than Montan wax. Montan wax,although it is a desensitizer against shock and impact, acted to reducethe time considerably for explosion to occur.

EXAMPLE 2 In the case of explosive mixtures of TNT and aluminum powder,the following times were measured at 340 C. for flashin or explosion totake place.

30 parts TNT, 33 parts powdered aluminum, parts Nibrenwachs D 116 N(softening point 116 C.) 65

This example, too, clearly demonstrates an improvement in thedesensitizing action when Nibrenwachs is used.

EXAMPLE 3 The desensitizing action of the Nibrenwachs against thermalstresses in explosives of the Composition B type is readily apparent.The Montan wax content was increased to 5 parts and the mixture againtested. However, the time of 32 seconds would not be improved on at thistemperature.

EXAMPLE 4 In the case of explosive mixtures of TNT, hexogen and powderedaluminum, the following times were measured at 235 C. for producingflashing or explosion. In addition, the following specific weights weredetermined:

Time

Spec. Wt. (seconds) 35 parts TNT, 40 parts hexogen, 25 parts powderedaluminum 30 parts TNT, 40 parts hexogen, 25 parts powdered aluminum, 5parts desensitlzer, consisting of: 4.2 parts parailln wax, 0.7 partsnitrocellulose, 0.1 part part lecithin 30 parts TNT, 40 parts hexogen,25 parts powdered aluminum, 5 parts Nibrenwachs D 130 30 parts TNT, 40parts hexogen, 25 parts powdered aluminum, 4.5 parts Nibrenwachs D 130,0.5 parts paraifin wax The desensitizing action and the improvement indensity brought about by the addition of Nibrenwachs are clearlyapparent in this example. The simultaneous use of soluble Nibrenwachsand of emulsion-forming paraffin wax improves the casting propertiessomewhat, without, however, reducing safety from thermal stress.

EXAMPLE 5 The following times were determined for explosive mixtures oftetryl and TNT (tetrytol) at 230 C. for producing flashing or explosion:

Seconds 70 parts tetryl, 30 parts TNT 28 69 parts tetryl, 30 parts TNT,1 part Montan wax 32 69 parts tetryl, 30 parts TNT, 1 part Nibrenwachs DEXAMPLE 6 In the case of explosive mixtures of TNT andnitropentaerythrite [=PETN], the following times were determined at 230C. for producing flashing or explosion:

Seconds 50 parts TNT, 50 parts nitropentaerythrite 27 50 parts TNT, 49parts nitropentaerythrite, 0.84 parts paraffin wax, 0.14 partsnitrocellulose, 0.02 parts lecithin 31 50 parts TNT, 49 partsnitropentaerythrite, 1 part Nibrenwachs D 116 35 4 EXAMPLE 7 Explosivemixtures of tetryl, trinitrobenzene and hex0-' gen were prepared andevaluated for the time required at 230 C. to produce flashing orexplosion. The following data were obtained:

Seconds 16 parts tetryl, 24 parts trinitrobenzene, 60 parts hexogen 4516 parts tetryl, 24 parts trinitrobenzene, 59 parts hexogen, 1 partMontan wax 44 16 parts tetryl, 24 parts trinitrobenzene, 59 partshexogen, 1 part Nibrenwachs D 55 The improvement in the desensitizationproduced by the use of Nibrenwachs in accordance with the invention isreadily apparent from Examples 5 to 7.

We claim:

1. An explosive composition comprising a fusible aromatic nitro compoundselected from the group consisting of trinitrotoluene, 2,4,6trinitrophenylmethylnitramine, and trinitrobenzene and a wax asdesensitizer consisting of a mixture of polychloronaphthalenes obtainedin the chlorination and refinement of naphthalene.

2. An explosive composition according to claim 1 additionally containingat least one member selected from the group consisting of nitramines,nitric esters and powdered metals.

3. An explosive composition according to claim 1 comprising 30 partstrinitrotoluene and 5 parts of a wax consisting of a mixture ofpolychloronaphthalenes obtained in the chlorination and refinement ofnaphthalene, having a softening point of 130 C.

4. An explosive composition according to claim 1 comprising 30 partstrinitrotoluene, 33 parts powdered aluminum and 5 parts of a waxconsisting of a mixture of polychloronaphthalenes obtained in thechlorination and refinement of naphthalene, having a softening point of116 C.

'5. An explosive composition according to claim 1 comprising 39 partstrinitrotoluene, 60 parts cyclotrimethylenetrinitramine, and 1 part of awax consisting of a mixture of polychloronaphthalenes obtained in thechlorination and refinement of naphthalene, having a softening point of116 C.

6. An explosive composition according to claim 1 comprising 30 partstrinitrotoluene, 40 parts cyclotrimethylenetrinitramine, 25 partspowdered aluminum, and 5 parts of a wax consisting of a mixture ofpolychloronaphthalenes obtained in the chlorination and refinement ofnaphthalene, having a softening point of 130 C.

7. An explosive composition according to claim 1 comprising 69 parts,2,4,6 trinitrophenylmethylnitramine, 30 parts trinitrotoluene and 1 partof a wax consisting of a mixture of polychloronaphthalenes obtained inthe chlorination and refinement of naphthalene, having a softening pointof 130 C.

8. An explosive composition according to claim 1 comprising 50 partstrinitrotoluene, 49 parts pentaerythritol tetranitrate, and 1 part of awax consisting of a mixture of polychloronaphthalenes obtained in thechlorination and refinement of naphthalene, having a softening point of116 C. i

9. An explosive composition according to claim 1 comprising 16 partstetryl, 2,4,6 trinitrophenylmethylnitramine, 24 parts trinitrobenzene,59 parts cyclotrimethylenetrinitramine, and 1 part of a Wax consistingof a mixture of polychloronaphthalenes obtained in the chlorination andrefinement of naphthalene, having a softening point of 130 C.

10. An explosive composition according to claim 1, wherein said wax ispresent in a ratio of 1 part wax: 5

to 100 parts explosive components comprising a fusible aromatic nitrocompound and mixtures thereof with at least one member of the group ofnitramines, nitric esters and powdered metals.

11. A method of desensitizing explosive compositions comprising fusiblearomatic nitro compounds selected 5 6 References (Zited UNITED STATESPATENTS 2,982,641 5/1961 Dawson et al. 149-105 X 3,000,720 9/1961 Baeret al 149105 X CARL D. QUARFORTH, Primary Examiner S. I. LECHERT,Assistant Examiner.

US. 01. X.R. 171-93, 94; 149 105, 106, 107

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3 72,713 DatedOct. 14, 1969 ADOLF BERTHMANN and PAUL LINGENS Patent No.

Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

F- Column 1, line 29, cancel the period 'after "naphthalene" and inserta comma; column 1, lines 35-36, "Nibrenwaches." should be-Nibrenwachse.-; column 1, line 47, "exacple" should be -examp 9 SIGNEDAND SEALED JUL? 1970 (SEAL) 'Attestr Edward M. Fletcher, Ir.

WILLIAM E. 'SOHUYLER. JR Amstmg Officer Commissioner of a

